day46-Django校验登录状态

一、使用装饰器校验登录状态

1.装饰器
(1)外层函数内嵌内层函数
(2)外层函数返回内层函数
(3)内层函数调用外层函数的参数

def is_login(func):

    def check_status(request):
        pass
    return check_status

2.定义装饰器

from django.http import HttpResponse, HttpResponseRedirect
from user.models import MyUser, TokenUser


def is_login(func):

    def check_status(request):
        token = request.COOKIES.get('token')
        if token:
            token_user = TokenUser.objects.filter(token=token).first()
            if token_user:
                # return func(request)表示继续执行被is_login装饰的函数
                return func(request)
            else:
                return HttpResponseRedirect('/login/')
        else:
            return HttpResponseRedirect('/login/')
    return check_status


@is_login
def my_index(request):
    if request.method == 'GET':
        return render(request, 'index.html')

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二、使用中间件校验登录状态

1.修改settings.py配置文件

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'utils.middle_ware.LoginStatusMiddleware',
]

2.定义中间件

from django.utils.deprecation import MiddlewareMixin
from django.http import HttpResponse, HttpResponseRedirect
from user.models import TokenUser


class LoginStatusMiddleware(MiddlewareMixin):

    def process_request(self, request):
        # 在访问登录和注册页面的时候，不需要做以下的登录校验功能
        if request.path in ['/login/', '/register/']:
            return None

        # 登录校验
        token = request.COOKIES.get('token')
        if token:
            token_user = TokenUser.objects.filter(token=token).first()
            if token_user:
                return None
            else:
                return HttpResponseRedirect('/login/')
        else:
            return HttpResponseRedirect('/login/')

    def process_response(self, request, response):
        return response

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三、session实现登录和校验登录状态

1.实现登录操作
(1)向cookie中设置session_id值，value为随机字符串
(2)向django_session表中存入session_id值，并保存键值对

from django.http import HttpResponse, HttpResponseRedirect
from user.models import MyUser, TokenUser


def login(request):
    if request.method == 'GET':
        return render(request, 'login.html')

    if request.method == 'POST':
        # 1.获取登录提交的用户名和密码
        username = request.POST.get('username')
        password = request.POST.get('password')

        # 2.查询数据库中用户名和密码对应的用户对象
        user = MyUser.objects.filter(username=username, password=password).first()

        if not user:
            err = '用户名或者密码错误!'
            return render(request, 'login.html', {'err': err})
      
        # 3.使用session实现登录操作
        request.session['user_id'] = user.id

        # 4.跳转到首页
        res = HttpResponseRedirect('/my_index/')
        return res

2.校验登录状态
session校验
(1)获取cookie中的session值
(2)查询django_session表中的session_key字段，查询到数据，则获取session_data中存入的键值对

from django.utils.deprecation import MiddlewareMixin
from django.http import HttpResponse, HttpResponseRedirect
from user.models import TokenUser, MyUser


class LoginStatusMiddleware(MiddlewareMixin):

    def process_request(self, request):
        if request.path in ['/login/', '/register/']:
            return None
        user_id = request.session.get('user_id')
        if user_id:
            # 向request.user中赋值，赋值为当前登录系统的用户对象
            user = MyUser.objects.get(pk=user_id)
            request.user = user
            return None
        else:
            return HttpResponseRedirect('/login/')

    def process_response(self, request, response):
        return response

3.注销
(1)删除cookie中的session_id值
(2)或者删除django_session表中的数据

def logout(request):
    # 方法1：删除客户端cookie中的数据以及django_session表中的数据
    request.session.flush()

    # 方法2：删除django_session表中的数据
    # request.session.delete(request.session.session_key)

    # 方法3：删除session_data中登录成功后设置的键值对
    # del request.session['user_id']

    return HttpResponseRedirect('/login/')

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